The warning in this case is that if you move your Master Palette directory to another location, you may loose the palette in your scene. The palette file is probably stored in a Master Palette directory on a hard drive external to the palette-libraries planned for the palette storage. Indicates that the palette file is stored in a directory external to the scene’s structure. For example, the palette file is stored in the scene folder and is linked to the Scene Palette List. There won’t be any problems once the scene is exported. These icons represent the palette's link status. You will notice that when you create or link a palette, a small icon appears on its left. It is always safer to have the palettes contained within the database to avoid data loss if the source palette were to be deleted or the project exported without including the external palettes. Harmony lets This method is not recommended. When the palette is imported in your scene, the file is copied in the project’s directory. If you created a palette in another project and you want to import it in your current project, you can browse for the palette file on your computer and add it to your scene. If your palette is linked to the Scene Palette list, it will be accessible by all layers. In order for both layers to access the palette, you must link both Element Palette lists to that palette. A good example would be a scene where there is a character on one layer and its arm is on another.
If you need that palette in a second layer, you can link the palette to the second layer's palette list. You may encounter a case where only a colour palette is visible when a layer is selected. You can do so by linking colour palettes to your palette lists.
Before starting colouring work such as ink and paint or even creating new colour models, you may want to load existing colour palettes to your scene.